Troubleshooting Image Defect - Brother HL-5240 Service Manual

6.3

Troubleshooting Image Defect

Several types of the image defects can be cleared by end users. For those defects, instruct
the user to check the 'User Check' items described in each table. Even if the same image
defect appears, the following procedures should be followed in the event of specific image
defects.
See also 6.4 "Location of Ground Contacts" in this Chapter
the grounding contacts.
!
CAUTION:
When using the printer for a special job, such as printing of name cards, print quality cannot be
guaranteed.
(I-1) Light
(1) Check the printer's environment. Conditions such as humidity, high
(2) If the whole page is light, toner save mode may be on. Disable toner save mode
(3) Try installing a new toner cartridge or drum unit.
Possible cause Step
Toner sensor 1
failure
(printer side)
Toner sensor 2
failure
(toner cartridge
side)
Drum 3
connection
failure
HVPS / Main 4
PCB failure
Dirt on the 5
scanner window
Laser unit failure 6
User Check
temperatures, etc. may cause this situation to occur.
within Printer Properties tab of the driver.
Check
Can printing be started with the
drum unit and toner cartridge
removed?
Is the problem solved when 4
or 5 pages are printed after the
toner cartridge is replaced with
a full one?
Are all the contacts between
the drum unit and printer body
connected correctly?
Is the harness connection
between the HVPS and the
main PCB correct?
Is there any dirt on the scanner
window?
Is the problem solved after
replacing the laser unit?
HL-5240/5250DN/5270DN/5280DW SERVICE MANUAL
for information about the location of
Result
Yes Check if the toner
sensor is dirty and
check the toner
sensor connection.
Yes The wiper of the toner
cartridge is defective.
Replace the toner
cartridge.
No Clean contact
electrodes both on the
drum unit and in the
printer body.
Yes Replace the HVPS or
the main PCB.
Yes Wipe it off with a soft
clean paper.
Yes Replace the laser unit.
4-39
Ground
Remedy
contacts
(1), (4),
(5), (6)
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